logically that means its ok for border morris dancers to wear black masks, but not black on their faces

They are not wearing masks though are they, Dick? We have no idea if anyone would take offense at them wearing black masks because they do not do it. The point is that anything done, even if done with the most innocent of intentions, can cause offense and, if it can it most likely will at some point. No one is saying don't do it. Just be aware of the possible repercussions. Like anything really!

DtG